package own.stu.jobgib.playown.alg.leetcode.editor.cn;

//给定M×N矩阵，每一行、每一列都按升序排列，请编写代码找出某元素。 
//
// 示例: 
//
// 现有矩阵 matrix 如下： 
//
// [
//  [1,   4,  7, 11, 15],
//  [2,   5,  8, 12, 19],
//  [3,   6,  9, 16, 22],
//  [10, 13, 14, 17, 24],
//  [18, 21, 23, 26, 30]
//]
// 
//
// 给定 target = 5，返回 true。 
//
// 给定 target = 20，返回 false。 
// Related Topics 双指针 二分查找 分治算法 
// 👍 25 👎 0



public class SortedMatrixSearchLcci{
    public static void main(String[] args) {
        Solution solution = new SortedMatrixSearchLcci().new Solution();
        System.out.println(solution.searchMatrix(new int[][]{
                {1, 4, 7, 11, 15},
                {2, 5, 8, 12, 19},
                {3, 6, 9, 16, 22},
                {10, 13, 14, 17, 24},
                {18, 21, 23, 26, 30}
        }, 20));
    }

    //leetcode submit region begin(Prohibit modification and deletion)
    class Solution {
        public boolean searchMatrix(int[][] matrix, int target) {
            if (matrix == null || matrix.length <= 0 || matrix[0].length <= 0) {
                return false;
            }

            int n = matrix.length;
            int m = matrix[0].length;

            int i = 0, j = m - 1;
            while(i < n && j >= 0){
                if(matrix[i][j] == target){
                    return true;
                }else if(matrix[i][j] > target){
                    j --;
                }else {
                    i ++;
                }
            }
            return false;
        }
    }
    //leetcode submit region end(Prohibit modification and deletion)

}
